1. Field of the Invention
The present invention relates to a liquid crystal display, and more particularly, to a liquid crystal display in which a photoelectric conversion element is provided on an unused space in a color filter layer to obtain image information of a subject facing an image display surface.
2. Description of the Related Art
Liquid crystal displays (LCD) are widely used in instruments and office automation apparatus and TV sets as well as portable electronic calculators and clocks.
Referring to FIG. 1 showing a conventional LCD, a liquid crystal layer 4 is formed between a first transparent substrate 1 and a second transparent substrate 2 which are arranged parallel to each other. A color filter layer 9 is formed on a facing surface of the first transparent substrate 1. Also, first and second electrode layers 5 and 6 for driving liquid crystals are formed on facing surfaces of the color filter layer 9 and the second transparent substrate 2, respectively. Liquid crystals of the liquid crystal layer 4 sealed by a sealant 3 become aligned in a predetermined direction by alignment layers 7 and 8. First and second polarizing plates 10 and 11 are provided on upper and lower portions of the first and second transparent substrates 1 and 2.
As shown in FIG. 2, the color filter layer 9 includes red(R), green(G) and blue(B) color filter plates 12 repeatedly arranged at predetermined intervals. The color filter layer 9 has a black matrix 13 for blocking light coming through intervals between the color filter plates 12. The black matrix 13 is an unused space on which no image is formed and covers most of the image display area. Meanwhile, bilateral image communication requires additional means for picking up a subject as well as a display for displaying an image, i.e., a CCD camera.